SaaS metrics
What is Magic Number?
Magic Number measures how much new ARR each R$ spent on sales and marketing generates — the gauge for whether to accelerate or slow investment.
Magic Number divides annualized MRR change by previous-quarter S&M spend. Above 1 means accelerate; between 0.5 and 1, hold steady; below 0.5, pull back.
It is popular with SaaS boards because it summarizes acquisition efficiency in a single number, without the noise of complicated payback math.
Formula
Magic Number = (ΔMRR trimestre × 4) ÷ S&M trimestre anteriorUse it in practice
SaaS Simulator
Frequently asked questions
When is Magic Number reliable?
After at least 4 quarters of stable data — shorter cycles carry too much seasonal noise.
Does a high Magic Number always mean "invest more"?
No. First confirm operational capacity (onboarding, support) to absorb the growth.